Regulation of protein kinase C in the muscular layer of human placental stem villi vessels.
Protein kinase C (PKC) activity in the muscular layer of stem villi vessels from the human term placenta was studied. Resting state PKC activity was distributed evenly between the cytosol and the particulate fractions. Upon stimulation by three different activators, phorbol 12-myristate 13-acetate, fluoride and endothelin-1, a translocation of PKC activity from the cytosolic to the particulate fraction was observed. The expression and distribution of PKC isoforms were then examined by Western blot analysis using specific antibodies to PKC isoforms. At least four PKC isoforms, PKCalpha, PKCbeta1, PKCbeta2, PKCzeta, and trace amounts of PKCepsilon were detected in both fractions. Their relative responses to the different agonists were examined by quantifying their subcellular redistribution. No significant differential activation of the four mainly expressed PKC isoforms were observed in response to stimulation with any of the stimuli. Moreover, our results show that endothelin-1 induced translocation/activation of PKC in this vascular smooth muscle.
Tertrin-Clary
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INSERM U. 361, Université René Descartes, Paris, France. u361@cochin.inserm.fr
Fournier
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Ferré
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D015153:Blotting, Western; D002462:Cell Membrane / Q000201:enzymology; D003600:Cytosol / Q000201:enzymology; D019332:Endothelin-1 / Q000494:pharmacology; D004789:Enzyme Activation / Q000502:physiology; D005459:Fluorides / Q000494:pharmacology; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000201:enzymology*; D010766:Phosphorylation; D010920:Placenta / Q000201:enzymology*; D011493:Protein Kinase C / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate
D019332:Endothelin-1; D007527:Isoenzymes; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D005459:Fluorides